There have been various techniques for detecting deformations such as cracks and lifts generated on a structure to be inspected. Patent Literature 1 discloses a technique for diagnosing cracks or the like by combining measurement results obtained using various instruments such as an image instrument, an infrared ray detector, and a non-contact type electromagnetic wave radar as well as diagnostic results obtained using a hammering method, a visual check method, or the like. Patent Literature 2 discloses a technique for diagnosing cracks or the like by superimposing visible and infrared images of an inspection target.